Selective Catalytic Reduction (SCR) systems are used to reduce nitrogen oxide compounds from the exhaust gases of, for example, power plants, marine vessels, and automobiles by injection of a liquid reagent into the exhaust gas stream. As emissions standards have become more stringent and SCR technology has become more widely adopted, the reagent delivery volume and pressure requirements have increased to achieve finer atomization of the reagent liquid by the delivery or dosing unit, among other reasons. However, delivering large liquid volumes at high pressure requires relatively large pumps and powerful motor assemblies, which increases the size, weight, energy requirements, and costs of the SCR system. Accordingly, improvements to SCR systems are desirable.